Dear Maintainer, after purging and reinstalling akonadi-backend-mysql kaddressbook works fine again. But akonadi-server should work without this backend. At least the dependencies declare: Depends: akonadi-backend-mysql (= 4:16.04.3-2) | akonadi-backend-sqlite (= 4:16.04.3-2) | akonadi-backend-postgresql (= 4:16.04.3-2) And the other two backends were installed! Klaumi ----------- Klaus-Michael Klingsporn mail: klaumikli@gmx.de web: www.klaumikli.de